Wireless communication system has been rapidly developed until now. The previous second generation mobile communication system GSM evolves continuously toward such techniques as general packet radio service (GPRS), EDGE with improved data rate, greatly enhancing the data transmission capability of the system. The third generation mobile communication system with higher transmission rate such as wideband code division multiple access (WCDMA, CDMA2000, etc.) has been deployed in many countries and districts in the world and put into commercial use. At the same time with the development of cellular communication techniques, other wireless access techniques such as wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) have also been rapidly developed. Furthermore, the fourth mobile communication system oriented technique of IEEE 802.16m and the third Generation Partnership Project Long Term Evolution (3GPP LTE), the third Generation Partnership project Long Term Evolution-Advanced (3GPP LTE+), etc., have also been started and entered into the level of research and development.
Demand for high speed multimedia communication and the access service for high speed wireless internet has been increased very fast, and the wireless spectrum resource is limited, therefore it is a problem waiting to be solved how to sufficiently enhance the transmission rate of the communication system and spectrum utilization ratio with use of the available band resource. Considering that multi-antenna technique can improve transmission capacity or signal quality, the above-mentioned various systems all adopt multi-antenna technique, and even an antenna mode including 8 transmission antennas and 8 receiving antennas from the base station to the mobile station has been defined in 3GPP LTE-Advanced system and IEEE 802.16m.
The space-time processing technique of multi-antenna system mainly includes space multiplexing and space diversity, etc. Space diversity is to divide the data into multiple data substreams by space-time encoding and the data substreams are transmitted over multiple antennas, and acquire diversity gain by introducing encoding redundancy in the time domain between the transmission antennas. Space multiplexing is to transmit separate information stream on the transmission antenna, and decode by the receiving terminal using interference suppressing, to thereby achieve maximum rate. Generally speaking, the space multiplexing technique may be used to enhance the throughput of the wireless communication system, while the space diversity technique may be used to enlarge the coverage of the wireless communication system.
In the wireless communication system, due to long distance from the service base station, the users at cell-edge receive a weaker signal from the service base station, and are subjected to a great interference from signals of base stations in nearby cells, thereby deteriorating the system throughput of the users at cell-edge.
Several references and literatures related with MIMO collaborative communication are listed below, which are incorporated herein by reference, as if they were described in detail in the specification.
1. [patent reference 1]: COX TIMOTHY [US]; KHOSHNEVIS AHMAD [US], COOPERATIVE MULTIPLE ACCESS IN WIRELESS NETWORKS (WO2008157147);
2. [patent reference 2]: SHEN MANYUAN [US]; XING GUANBIN [US], Cooperative MIMO in Multicell wireless networks (US2008260064);
3. [patent reference 3]: LI ANXIN [CN]; LI XIANGMING [CN], UPLINK MULTIPLE-INPUT-MULTIPLE-OUTPUT (MIMO) AND COOPERATIVE MIMO TRANSMISSIONS (WO2008124535);
4. [patent reference 4]: MEHTA NEELESH B [US]; ZHANG HONGYUAN [US], System and method for transmitting signals in collaborative base station multi-user MIMO networks (US2007248172);
5. [patent reference 5]: KIM SUNG JIN [KR]; KIM HO JIN [KR], METHOD FOR COOPERATIVE DIVERSITY IN MIMO WIRELESS NETWORK (KR20060111238);
6. [patent reference 6]: KIM SUNG-JIN [KR]; KIM HO-JI [KR], Method of providing collaborative diversity in a MIMO wireless network (US2006239222);
7. [patent reference 7]: PCT application WO2008/151534, entitled “MULTI-ANTENNAE SYSTEM AND DATA TRANSMITTING METHOD”, MATTIAS, Wennstrom, et al . . . .
8. [patent reference 8]: Chinese patent application CN101039137A, entitled “Method and system for reducing codebook search-based pre-coding feedback bits of MIMO-OFDM system”, YANG BO, etc;
9. [non-patent literature 1]: Ayman F. Naguid, Vahid Tarokh, Nambirajan Seshadri, A. Robert Calderbank, “A Space-Time Coding Modem for High-Data-Rate Wireless Communications,” IN IEEE JSAC, vol. 16, no. 8, October 1998, pp. 1459-1478.
10. [non-patent literature 2]: V. Tarokh, N. Seshadri, A. R. Calderbank, “Space-time codes for high data rate wireless communication: performance criterion and code construction”, IEEE Trans. Inform. Theory, 44:744-765, March 1998.